Garcia Nicole, Raimbault Patrick, Gouze Emma, Sandroni Valérie
Laboratoire d'océanographie et de Biogéochimie, Centre d'océanologie de Marseille, CNRS, Université de la Méditerranée, 163, av. de Luminy, case 901, 13288 Marseille cedex 9, France.
C R Biol. 2006 Sep;329(9):742-50. doi: 10.1016/j.crvi.2006.06.006. Epub 2006 Jul 26.
Nitrogen fixation, nitrate assimilation and primary production ((13)C/(15)N method) were investigated during one year and half in the northwestern Mediterranean Sea. Nitrogen fixation was detectable all over the year with rates ranged from 2 to 17 nmol N l(-1) d(-1)(d). Highest values being obtained during spring associated with the phytoplankton bloom. High rates (4-8 nmol N l(-1) d(-1)(d)) were also measured during summer, when primary productivity was very low. Then, diazotrophy process supplies significant new nitrogen during summer oligotrophic periods. This new nitrogen input can balance the annual nitrogen biogeochemical budget in the Mediterranean Sea and should explain the high nitrate/phosphate ratio observed in deep waters.
在地中海西北部，对固氮作用、硝酸盐同化作用和初级生产力（采用(13)C/(15)N方法）进行了为期一年半的研究。全年都可检测到固氮作用，速率范围为2至17 nmol N l(-1) d(-1)（d）。春季与浮游植物大量繁殖相关时获得最高值。夏季初级生产力非常低时也测得较高速率（4 - 8 nmol N l(-1) d(-1)（d））。那么，在夏季贫营养期，固氮过程提供了大量新的氮。这种新的氮输入可以平衡地中海的年度氮生物地球化学收支，并且应该可以解释在深层水体中观察到的高硝酸盐/磷酸盐比值。
